The present invention relates to the field of video recording devices and, more particularly, to personal video recording devices that buffer the video signal for a predicted digital television channel.
Personal video recording (PVR) devices have gained popularity in recent years in part because they allow a viewer to watch a received broadcast or other transmitted video or television signal and while watching the received program, pause, rewind, and fast forward the program by virtue of the signal content being buffered for time shifting. For example, as a viewer is watching a program, the user may pause the viewing while the received signal content continues to be buffered. When the viewer is ready to resume viewing, the program is continued from the pause point in the buffer as new content continues to be added to the buffer. Buffering allows viewers to skip commercials, halt viewing to engage in some other activity, and re-watch portions of a program at their leisure.
The first PVRs had a single tuner and used a single buffer, which only buffered the channel being watched. The buffering of only a presently viewed channel, however, is limiting. Only the presently viewed channel is buffered and available for time-shifted viewing. When a user changes channels, the buffer is generally re-initialized, losing the previously buffered video data. Thus, a user of the PVR loses the ability to perform time-shifting operations for a buffered program upon return to that channel.
For example, when a user watches a news program on Channel A, the news program is buffered in the PVR. When the user changes to Channel B to check the score of a sports game, the news program data is purged and the sports game starts to be buffered. After seeing the score, the user then returns to Channel A. The buffer is again purged and the PVR begins storing the data for the news program from the current point in time; the user cannot rewind the news program to view the content for the time period spent viewing Channel B.
To overcome this issue, dual-tuner PVRs have been developed, which allow a user to record one channel while watching and buffering another channel. However, dual-tuner PVRs require manual programming of the secondary channel for buffering. Neither approach attempts to anticipate user channel changes.